Since the early days of cellular telephony one of the key aspects of system design has been to provide signal to locations where the customers are located and to prevent the signal from propagating further than necessary, thereby causing interference to others and reducing the overall system capacity and performance.
Working within the constraint posed by a fixed cell site location, by the 1980's there were four accepted techniques that could be used to affect the coverage of a cell. These were needed to insure that the cell provided coverage in the areas where customers are located and did not provide excessive interference in other areas. Three of the four techniques were based on deployment of the antenna at the cell site. The antenna height on the tower could be changed, the antenna azimuth could be changed, or the downtilt of the antenna could be changed. The fourth technique involved the modification of the transmit power on the broadcast system information and/or paging channels. This later technique was not widely used in practice except for limited special cases. In the late 1980's when the GSM digital cellular system was being developed, a fifth technique became available, the modification of various system parameters which control mobile station operation. For example, it was suggested in the GSM Phase I recommendations that the handover thresholds could be used to adaptively control cell sizes to meet the needs of spatially varying traffic loading over time. The first three techniques described above are commonly referred to as physical techniques while the latter two are commonly referred to as electrical techniques.
The actual decision to adjust a cell using one of the 5 techniques cited above has typically relied on both the good intuition of the RF planner as well as extensive analysis done via an RF planning tool. Thus it is generally accepted that significant effort, and therefore cost, is required to plan these changes and even more to deploy them as traditional cellular providers have focused primarily on the physical techniques which require sending a service crew to the cell site to make modifications to the antennas. Less attention has been paid to the electrical techniques as they are as not as well understood within the industry. With the introduction of CDMA technology in the 1990's this became even more the case as the CDMA system has many more parameters that can be adjusted and they are intimately related to each other in complex ways. This has motivated cellular providers to adhere to the manufacture default settings and to continue to focus exclusively on the well understood physical modifications. Indeed, a market for consulting services in the area of cell site adjustments for capacity planning has arisen as service providers do not have the staff and time to affect the needed physical adjustments.
The function of the Telcordia Auto RF product is to perform the cell site capacity optimizations using the electrical techniques rather than the physical techniques. Electrical modifications can be implemented more rapidly and at significantly reduced costs. Therefore, significant benefits can be seen by service providers. While the analysis techniques, methods, and procedures to support physical changes are well understood within the industry and have been incorporated into many RF planning tools, the methodology to support electrical changes based on actual network traffic measurements is not available in the public domain, nor are they presently supported within the RF planning tool industry.